Sheer Genius
by Laurus Nobilis
Summary: Doctor Who and xxxHOLiC crossover. The Doctor takes Martha to visit two of his oldest friends.


**Disclaimer:** Doctor Who belongs to the BBC, xxxHOLiC belongs to CLAMP.

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**Sheer Genius **

When Martha opened the TARDIS's door, she discovered that it hadn't landed on a relatively deserted place, as it did most of the time. They were in someone's garden. A large house built in a vaguely Asian style stood right in front of her.

"Are you sure this is all right?" she asked. "It doesn't look empty. People will freak out when they see the TARDIS."

"Oh, don't worry about that," said the Doctor, already on his way to the building. "It's an old friend's place. I bet she's expecting us, even."

"Wait, when did you warn that friend of yours that we were coming? I don't remember you calling or anything."

"I didn't. No need," he replied. "Ah, there she is! And she's got company."

Martha followed his gaze and discovered two figures sitting on the gallery. One of them was a very beautiful woman; the other one was a tall, bespectacled man. They put down their teacups when they saw the visitors coming, but the Doctor had jumped onto the gallery before they had time to stand up.

"Yuuko! It's good to see you again. How long has it been? I know I haven't seen _you_ since that time on the pirate ship, Clow, that one's kind of hard to forget. You look great, both of you! You haven't changed at all."

"You have," Yuuko pointed out. "And so has your companion."

"Hi," said Martha, waving a little.

"Oh, right, almost forgot the introductions!" the Doctor exclaimed. "This is Yuuko Ichihara, the Witch of Dimension. Clow Reed, most powerful wizard in the world. Martha Jones, soon to be a medical doctor."

"Pleased to meet you, Miss Jones," said Clow. "Biscuit?"

"Sure, thanks," she replied, taking one from the tray he offered her. Following the Doctor's lead, she took off her shoes and sat next to the others. "So... a witch and a wizard, then?"

Yuuko laughed and gave her a knowing look.

"He's already given you his little speech about magic, hasn't he?"

"He did," Martha confirmed, not even bothering to hide her amusement at the Doctor's offended expression. "Back when we met the witches from Macbeth – the inspiration for them, I mean."

"Well," said Clow, smiling at her, "you can see that he isn't _always_ right, no matter how much he tries to pretend otherwise."

"Oh, look who's talking!" the Doctor replied. "The truth is, it's all a matter of wording, really. If you want to call what you do 'magic', go ahead, ignore all my perfectly reasonable scientific explanations."

"But wording makes all the difference," the wizard insisted. "You have no sense of poetry whatsoever."

"What? Science _is_ poetry –"

"Certainly not. There's no poetry in a man who would look at a magical air sprite and call her an artificial nitrogen-based lifeform sustained by a telepathic link."

"No, I would call her _Windy_. I don't call you a carbon-based humanoid lifeform, do I?"

"Wait a second. Who's Windy?" asked Martha, in an attempt to satisfy her curiosity and stop them from rambling at the same time. Clow smiled proudly at her, and she had the distinct impression that he had been waiting for her to ask that precise question.

"She's one of my Cards," he explained. "Here, let me show you."

He took a deck with a dark red back from one of his pockets. For a moment, Martha thought that he was going to do one of those tricks she was used to; it was hardly the first time that she saw a magician play with cards. But he managed to surprise her. He picked one of them and, before she could realize what was going on, there was a flash of light – and then a winged woman floated between them, smiling gently.

"You're... wow, you're gorgeous," Martha told her. Then she turned to look at the wizard, who still stood nearby. "What _is _she?

"An artificial nitrogen-based lifeform sustained by a telepathic link," the Doctor said cheerfully. Clow rolled his eyes.

"Like I said, she's one of my Cards," he corrected. "A magical creature. Pretty, isn't she?"

"Very," Martha agreed. Windy smiled at her yet again, then disappeared with a flourish and returned to her card form.

"Can you stop showing off now?" Yuuko said with a bored expression. "I'm sure we all have more interesting things to talk about."

"Certainly! Want to hear how Martha and I saved the world last time?"

"No," the witch replied. "I want to hear what brings you to my house. It isn't easy to find, you know that."

"What does that mean?" Martha asked, confused.

"I grant people's wishes," Yuuko explained, "always for a price, of course. Only those who wish for something are able to enter my shop. Which means he needs my help."

"Which means he's been messing with the balance of the universe," Clow said with an amused smile. "Again."

"... oh, _that_. Yeah, he's definitely been doing that lately."

"You people make it sound like it was a _bad_ thing," the Doctor defended himself. "Anyway, my dear Yuuko, I must tell you that you're absolutely wrong this time. I have nothing specific to ask of you. It's more of a... general thing, really. Awfully expensive. Bet I can't afford to even think about it."

"No, you probably don't," she muttered, and for a moment she looked almost concerned about him. But a moment later she had regain her cheerfulness, and Martha couldn't help but wonder if she had imagined it. "So you're actually here to _visit_! Now, that counts as a special occasion. Bring on the sake, Clow! We've got to celebrate!"

"Ah, yes, always looking for excuses," he said good-naturedly, while he produced a bottle of sake seemingly out of nowhere. "But it's not going to be entirely a pleasure trip, I'm afraid. I do have a few questions for you, Doctor. I could use your help for this little thing I'm planning..."

"Am I going to like it?" the Doctor asked, suspicious. "Yuuko, do _you_ like it?"

"Not one bit. And you probably won't, either."

"Well, it doesn't hurt to ask, does it?" Clow said, frowning a little. "I just need to figure out a couple of details about cell death and renewal, that's all. I mean, I might be a genius, but it's not _my_ fault that people haven't even discovered DNA yet so I have no reading material –"

"That's right," the Doctor interrupted, "don't like it."

"... wow, even _I_ don't like it," Martha muttered, and then she grinned when she realized that everyone was looking at her. "Sorry. It's just – well, we've had trouble with this crazy guy who tried to mess with his DNA to look younger, or cheat death or something like that, and he ended up really bad. And did I mention crazy?"

"Oh, but I'm not trying to do _that_," Clow assured her, still smiling calmly. "I don't need any help to look young, if I may say so myself. And, well... I don't precisely intend to stay alive."

"All right, you've lost me there," said the Doctor, frowning at him. "What _exactly _are you planning to do? And how stupid is it this time?"

"It's not stupid. It's rather brilliant, in fact, and I'm sure you will agree when you hear the whole story. You see, I don't plan to stop my death. We all die eventually. I'm more concerned about what happens _after_ that..."

"Such a grim topic," Yuuko sighed, while he rambled on. The Doctor seemed very eager to interrupt him, but so far he'd managed to stop himself. Martha wasn't sure he'd last for long, though. The men seemed to get the hint, and they moved away from the others so they wouldn't bother them with their conversation.

"Indeed," she agreed, taking another biscuit; they were truly delicious. "But _they_ seem to find it interesting."

Now the Doctor had already lost control and they were both talking at the same time. Martha didn't even try to listen to what they were saying anymore. It was too fast, too messy, and too complicated.

"Well, they're crazy," Yuuko said. "I never thought someone could outtalk Clow Reed until I met this one. He's rather impressive, I've got to give him that."

"I honestly wonder how he manages to breathe sometimes," Martha said. "And how do they even understand each other?"

"Oh, I think they just guess," the witch said with a shrug. Then she turned to face her, with a dangerous smile on her face. "But we shouldn't let ourselves get distracted by their silly ramblings. The question is, why are _you_ here, Martha Jones?"

"What do you mean?"

"You're in my shop. You have a wish."

"Well, sure. Who doesn't? I've got plenty of wishes," Martha replied, trying to sound normal even though she felt a lingering nervousness for some reason. "I wish to pass my exams. I wish to be a good doctor, someday. I wish I could be more honest to Mum. I wish... yeah," she sighed after a short pause, "that's probably the one you were thinking about."

Yuuko followed her gaze, then smiled at her with a knowing look.

"But you aren't going to ask for anything," she said. Martha couldn't help but chuckle to herself.

"No," she agreed. "That kind of things... it's better if you get them on your own, isn't it? _If_ you get them at all. I mean, just because you wish for something doesn't mean it's good for you. I guess."

"Smart girl," Yuuko said, and she sounded like she meant it. "And trust me, you're better off this way. One day you find yourself admiring a genius, and next thing you know you're stuck with a smug, annoying, self-righteous idiot who just won't shut up."

"There's that, too," Martha laughed. "Look at them. It looks like they'll never stop."

"Oh, just wait until the part where they tell each other in detail how many times their sheer genius saved the universe since they last met," Yuuko muttered, rolling her eyes.

That would take quite a while, Martha thought. Even if the Doctor only mentioned what they'd done since he met her, it'd be enough for hours and hours. The TARDIS had taken them to so many places already... which reminded her of something, now that she thought about it.

"You know, there's something I don't understand," she asked. "What about the TARDIS? She's alive, and she's here. Does that mean she has a wish too? That'd be weird. Not as weird as _other_ things I'd seen lately, granted, but still – weird."

"I don't know about that," the witch said honestly. "The TARDIS is one of the very few things that functions on its own rules without clashing with _mine_. There's a lot of Time Lord science in it, and that's one of the rare things he _won't_ talk about. Believe me, Clow asked. A lot."

"I can see that," she cuckled, staring at the two men. The conversation (if it could even be called that) was still going strong. "They seem to have a lot in common, don't they?"

"All the annoying bits," Yuuko told her with a mean-looking grin. "At least the Doctor brings other people with him, most of the times he comes to visit. When those two start talking between each other there's just no way to stop them."

"No wonder you need the sake," the girl muttered. "They look happy, though."

And so they did. The Doctor looked was already walking around in circles and talking to himself, and Martha could tell it was a matter of seconds until he started bouncing al over the place. Clow was a lot more mild-mannered, but he didn't stop smiling, and his eyes shone with such a spark that anyone could tell he was truly enjoying himself.

"Hmmm, yes," said Yuuko softly. "That's the good part."

She had such a fond look on her eyes while she stared at them that Martha was about to make a probably rude question when the Doctor finally jumped up and approached them.

"So! Are there any biscuits left? We've just done a serious bit of thinking right now."

"And that makes you horribly hungry, of course," Yuuko teased him.

"You, my dear," said Clow, "aren't one to judge other people for how much they eat in relation to their work. And don't worry; I've made plenty of snacks. There are more inside the house."

"Good to hear that, because these are _great_," Martha told him. "Seriously."

"Oh, it's just one of the smallest of my abilities," he replied, obviously thinking he was being modest. Yuuko gave her an amused look and she had to try very hard not to laugh.

They didn't stay much longer, however. The Doctor never stayed for long in one place if he didn't have to save the universe, and not only this was a quiet day, but Clow and Yuuko were more than capable of saving the universe on their own. They finished the snacks, conversation died down, and at last both travellers returned to the TARDIS.

"You've got nice friends," Martha said once they were inside. "Weird, but nice."

"Of course they're nice! You didn't think I'd befriend nasty people, did you?"

"But what about his plan?" she asked. "You said you wouldn't like that."

"What wouldn't I... oh, the _plan_!" he exclaimed, and his eyes were bright when he grinned at her. "It's _brilliant_."

Martha didn't even try to understand.


End file.
